BROCKTON — Open-road tolling is an inexpensive prospect for the Massachusetts Department of Transportation to put in place, but the ease with which it can be implemented could spell more tolls for drivers outside the Interstate 90 corridor, according to Transportation Secretary Richard Davey.

"While it might not happen in my time," Davey told lawmakers Wednesday, the launch of open-road tolling -- which requires no tollbooths or toll collectors -- in Massachusetts will "set the table" for potential tolling on new roads.

"All electronic tolling we really think holds out a promise. And we mentioned this in our plan, potentially for future tolling in and around the state. It is certainly an equity issue in this Commonwealth when it comes to folks paying," Davey said, referring to the tolls along the Massachusetts Turnpike.

Addressing members of the House and Senate Ways and Means committees at a budget hearing, Davey said, "Although we need the federal government's approval if we wish to toll other interstates in the future -- 93, 95, 84, 91 -- one of the hurdles that has been said in the past is you have the cost of construction."

That is not an issue with open-road tolling, which uses EZ-pass technology, or cameras and a billing system, rather than toll booths. "Open road tolling is not expensive," Davey said.

He said the state's 1960s-era tollbooths would need to be rebuilt anyway, and the funds for switching to open-road tolling can come out of toll revenues.

One hitch is negotiations with the toll collectors, and Davey said he is hoping to find them new jobs in MassDOT or the private sector, though the negotiations have "been declared at an impasse."

Speaking about tolling gave Davey a chance to sound off on the neighbors to the south.

"The number one toll scofflaws are Connecticut residents. Unfortunately we can't collect yet with Connecticut residents because we don't have an agreement with the state of Connecticut," Davey said.

He said the state has an agreement with Maine and New Hampshire to collect tolls unpaid by drivers in those states.

Davey testified that open road tolling would begin soon, "starting with the Tobin Bridge later this year." Spanning the Mystic River from Charlestown to Chelsea, the Tobin Bridge has tolls on inbound side. "The Tobin Bridge is a very easy place to do it," Davey said.

In addition to lessening congestion and improving air quality, the Patrick administration estimates its all-electronic tolling plans could eventually reduce operating costs by $50 million a year, in part by replacing toll collectors.